▎ 摘　　要

NOVELTY - Agent comprises 4-8 pts. wt. ferric sulfate, 1-3 pts. wt. calcium hydroxide, 5-12 pts. wt. barium sulfide, 3-5 pts. wt. polyacrylamide, 15-27 pts. wt. fly ash, 8-15 pts. wt. carnallite, 10-18 pts. wt. aluminum ash, 2-5 pts. wt. Asparagus, 3-9 pts. wt. hyacinth, 50-75 pts. wt. crop waste, 25-40 pts. wt. urban sludge, and 6-15 pts. wt. graphene. USE - Agent for treating municipal sewage (claimed). ADVANTAGE - The agent has synergistic effect, strong ability, good economic benefit and social benefit and effectively precipitates heavy metal ion. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing agent, which involves: (A) crushing carnallite to 30-50 meshes and soaking into hydrochloric acid having mass concentration of 0.5-0.8mol/L for 25-40 minutes, and then placing under ultrasonic shock cleaning for 10-18 minutes, and then soaking into sodium hydroxide solution having concentration of 0.3-0.6mol/L for 12-25 minutes, and putting into deionized water to neutral, to get modified carnallite; (B) mixing modified carnallite, ferric sulfate, calcium hydroxide and barium sulfide into crusher to obatin 150-180 meshes powder, then adding polyacrylamide, heating to 110-130 degrees C for 4-6 hours to obtain first mixture; (C) crushing hyacinth and Asparagus, drying to obtain 20-50 meshes powder, and then soaking powder into anhydrous ethanol and then extracting to obtain extracting liquid, evaporating and concentrating the extracting liquid and drying to obtain hyacinth and Asparagus extraction powder; (D) drying the crop waste to moisture less than 3 wt.%, and then putting into calciner with urban sludge to obtain the second mixture; and (E) mixing first and second mixture, fly ash, aluminum ash and graphene, heating under stirring for 0.5-2 hours at 50-65 degrees C to obtain the finished product.